1. Field of the Invention
This invention relates to triphenylphosphine which is a useful reagent in polyene synthesis. 2. Description of the Prior Art
Triphenylphosphine can be recovered by the regeneration of triphenylphosphine oxide resulting from a polyene synthesis.
In a prior art process for recovering triphenylphosphine, triphenylphosphine oxide was chlorinated (e.g., by means of phosgene) to give triphenylphosphine dichloride. The latter compound was hydrogenated to yield triphenylphosphine. The hydrogenation of triphenylphosphine dichloride has hitherto been carried out, for example, with hydrogen under pressure (Angew. Chem. 89, 558 1977).
It has now been found that the hydrogenation of triphenylphosphine dichloride can be carried out in a very simple and advantageous manner with hydrogen in the presence of certain catalysts.